The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
A vehicle means a device that can carry people or goods to a destination while driving on roads or tracks. The vehicle can be moved to various positions mainly by using one or more wheels installed in the vehicle body. Such a vehicle may be a three-wheeled or four-wheeled vehicle, or a two-wheeled vehicle such as a motorcycle, a construction machine, a bicycle, and a train traveling on a rail arranged on a railroad.
Generally, a heating ventilation and air conditioning (HVAC) system includes a cooling system for cooling an interior of an automobile and a heating system for heating an interior of the automobile. Such an air conditioning system is a device for controlling air in a vehicle based on a method of obtaining a cold wind by using heat exchanged air by blowing air to the surface of the evaporator, since the refrigerant is compressed by using the power unit of the automobile and the refrigerant is condensed again into the outside air, then rapidly expanded and then evaporated, so that the refrigerant takes away heat from the outside when evaporating and becomes cold, and obtaining a hot wind by blowing air on the surface of a heater using cooling water heated by an engine using heat generated by burning fuel in a power generating device.
The air discharged from the air conditioning system is discharged to the inside of the vehicle through an air vent (air outlet) provided inside the vehicle. On the other hand, noise is generated due to rotation of the blower fan for blowing air generated from the air conditioning system.
Further, depending on a degree of opening or closing of the air vent, there is a restriction on the flow of air discharged into the vehicle interior, which may cause an increase in noise generated from the air conditioning system.
That is, as the degree of opening of the air vent is smaller, the flow of air is not smooth, so that the noise generated from the air conditioning system is increased.
In recent years, studies is being conducted to methods for removing noise by determining the degree of noise generated from the air conditioning system of a vehicle.